Merge "Add jackson behavior for fields"
diff --git a/gson/src/main/java/org/onap/policy/common/gson/JacksonFieldAdapterFactory.java b/gson/src/main/java/org/onap/policy/common/gson/JacksonFieldAdapterFactory.java
new file mode 100644
index 0000000..67c5144
--- /dev/null
+++ b/gson/src/main/java/org/onap/policy/common/gson/JacksonFieldAdapterFactory.java
@@ -0,0 +1,181 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2019 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.gson;
+
+import com.google.gson.Gson;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.TypeAdapter;
+import com.google.gson.TypeAdapterFactory;
+import com.google.gson.reflect.TypeToken;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
+import java.io.IOException;
+import java.lang.reflect.Field;
+import java.util.ArrayList;
+import java.util.List;
+import org.onap.policy.common.gson.internal.ClassWalker;
+import org.onap.policy.common.gson.internal.Deserializer;
+import org.onap.policy.common.gson.internal.FieldDeserializer;
+import org.onap.policy.common.gson.internal.FieldSerializer;
+import org.onap.policy.common.gson.internal.Serializer;
+
+/**
+ * Factory that serializes/deserializes class fields following the normal behavior of
+ * jackson. Supports the following annotations:
+ * <ul>
+ * <li>GsonJsonIgnore</li>
+ * <li>GsonJsonProperty</li>
+ * </ul>
+ *
+ * <p>Note: {@link JacksonExclusionStrategy} must also be registered with the gson object.
+ */
+public class JacksonFieldAdapterFactory implements TypeAdapterFactory {
+
+ @Override
+ public <T> TypeAdapter<T> create(Gson gson, TypeToken<T> type) {
+ Class<? super T> clazz = type.getRawType();
+
+ if (!JacksonExclusionStrategy.isManaged(clazz)) {
+ return null;
+ }
+
+ ClassWalker data = new ClassWalker();
+ data.walkClassHierarchy(clazz);
+
+ if (data.getInProps(Field.class).isEmpty() && data.getOutProps(Field.class).isEmpty()) {
+ // no fields to serialize
+ return null;
+ }
+
+ return new JacksonFieldAdapter<>(gson, data, gson.getDelegateAdapter(this, type));
+ }
+
+ /**
+ * Adapter for a single class.
+ *
+ * @param <T> type of class on which the adapter works
+ */
+ private static class JacksonFieldAdapter<T> extends TypeAdapter<T> {
+
+ /**
+ * Used to create an object of the given class.
+ */
+ private final TypeAdapter<T> delegate;
+
+ /**
+ * Used to serialize/deserialize a JsonElement.
+ */
+ private final TypeAdapter<JsonElement> elementAdapter;
+
+ /**
+ * Serializers for each item within the object.
+ */
+ private final Serializer[] serializers;
+
+ /**
+ * Deserializers for each item within the object.
+ */
+ private final Deserializer[] deserializers;
+
+ /**
+ * Constructs the object.
+ *
+ * @param gson the associated gson object
+ * @param data data used to configure the adapter
+ * @param delegate default constructor for the type
+ */
+ public JacksonFieldAdapter(Gson gson, ClassWalker data, TypeAdapter<T> delegate) {
+ this.delegate = delegate;
+
+ this.elementAdapter = gson.getAdapter(JsonElement.class);
+
+ // create serializers
+ this.serializers = makeSerializers(gson, data).toArray(new Serializer[0]);
+
+ // create deserializers
+ this.deserializers = makeDeserializers(gson, data).toArray(new Deserializer[0]);
+ }
+
+ /**
+ * Creates a complete list of serializers.
+ *
+ * @param gson the associated gson object
+ * @param data data used to configure the serializers
+ * @return a list of all serializers
+ */
+ private List<Serializer> makeSerializers(Gson gson, ClassWalker data) {
+ List<Serializer> ser = new ArrayList<Serializer>();
+
+ data.getOutProps(Field.class).forEach(field -> ser.add(new FieldSerializer(gson, field)));
+
+ return ser;
+ }
+
+ /**
+ * Creates a complete list of deserializers.
+ *
+ * @param gson the associated gson object
+ * @param data data used to configure the deserializers
+ * @return a list of all deserializers
+ */
+ private List<Deserializer> makeDeserializers(Gson gson, ClassWalker data) {
+ List<Deserializer> deser = new ArrayList<Deserializer>();
+
+ data.getInProps(Field.class).forEach(field -> deser.add(new FieldDeserializer(gson, field)));
+
+ return deser;
+ }
+
+ @Override
+ public void write(JsonWriter out, T value) throws IOException {
+ JsonElement tree = delegate.toJsonTree(value);
+
+ if (tree.isJsonObject()) {
+ JsonObject jsonObj = tree.getAsJsonObject();
+
+ // serialize each item from the value into the target tree
+ for (Serializer serializer : serializers) {
+ serializer.addToTree(value, jsonObj);
+ }
+ }
+
+ elementAdapter.write(out, tree);
+ }
+
+ @Override
+ public T read(JsonReader in) throws IOException {
+ JsonElement tree = elementAdapter.read(in);
+ T object = delegate.fromJsonTree(tree);
+
+ if (tree.isJsonObject()) {
+ JsonObject jsonObj = tree.getAsJsonObject();
+
+ // deserialize each item from the tree into the target object
+ for (Deserializer dser : deserializers) {
+ dser.getFromTree(jsonObj, object);
+ }
+ }
+
+ return object;
+ }
+ }
+}
diff --git a/gson/src/main/java/org/onap/policy/common/gson/internal/FieldDeserializer.java b/gson/src/main/java/org/onap/policy/common/gson/internal/FieldDeserializer.java
new file mode 100644
index 0000000..14a432d
--- /dev/null
+++ b/gson/src/main/java/org/onap/policy/common/gson/internal/FieldDeserializer.java
@@ -0,0 +1,72 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2019 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.gson.internal;
+
+import com.google.gson.Gson;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParseException;
+import java.lang.reflect.Field;
+
+/**
+ * De-serializer for fields that are exposed.
+ */
+public class FieldDeserializer extends Adapter implements Deserializer {
+
+ public static final String SET_ERR = "cannot set field: ";
+
+ /**
+ * Field within the object.
+ */
+ private final Field field;
+
+ /**
+ * Constructs the object.
+ *
+ * @param gson Gson object providing type adapters
+ * @param field field within the object
+ */
+ public FieldDeserializer(Gson gson, Field field) {
+ super(gson, field);
+
+ this.field = field;
+
+ field.setAccessible(true);
+ }
+
+ @Override
+ public void getFromTree(JsonObject source, Object target) {
+ JsonElement jsonEl = source.get(getPropName());
+ if (jsonEl == null || jsonEl.isJsonNull()) {
+ return;
+ }
+
+ Object value = fromJsonTree(jsonEl);
+
+ try {
+ field.set(target, value);
+
+ } catch (IllegalArgumentException | IllegalAccessException e) {
+ throw new JsonParseException(makeError(SET_ERR), e);
+ }
+ }
+
+}
diff --git a/gson/src/main/java/org/onap/policy/common/gson/internal/FieldSerializer.java b/gson/src/main/java/org/onap/policy/common/gson/internal/FieldSerializer.java
new file mode 100644
index 0000000..1c9d8b3
--- /dev/null
+++ b/gson/src/main/java/org/onap/policy/common/gson/internal/FieldSerializer.java
@@ -0,0 +1,80 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2019 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.gson.internal;
+
+import com.google.gson.Gson;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonNull;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParseException;
+import java.lang.reflect.Field;
+
+/**
+ * Serializer for fields that are exposed.
+ */
+public class FieldSerializer extends Adapter implements Serializer {
+
+ public static final String GET_ERR = "cannot get field: ";
+
+ /**
+ * Field within the object.
+ */
+ private final Field field;
+
+ /**
+ * Constructs the object.
+ *
+ * @param gson Gson object providing type adapters
+ * @param field field within the object
+ */
+ public FieldSerializer(Gson gson, Field field) {
+ super(gson, field);
+
+ this.field = field;
+
+ field.setAccessible(true);
+ }
+
+ @Override
+ public void addToTree(Object source, JsonObject target) {
+ Object value;
+ try {
+ value = getFromObject(source);
+
+ } catch (IllegalArgumentException | IllegalAccessException e) {
+ throw new JsonParseException(makeError(GET_ERR), e);
+ }
+
+ JsonElement jsonEl = (value == null ? JsonNull.INSTANCE : toJsonTree(value));
+ target.add(getPropName(), jsonEl);
+ }
+
+ /**
+ * Gets the field from the source object. Overridden during junit testing.
+ *
+ * @param source object containing the field
+ * @return the field's value
+ * @throws IllegalAccessException if an error occurs
+ */
+ protected Object getFromObject(Object source) throws IllegalAccessException {
+ return field.get(source);
+ }
+}
diff --git a/gson/src/test/java/org/onap/policy/common/gson/JacksonFieldAdapterFactoryTest.java b/gson/src/test/java/org/onap/policy/common/gson/JacksonFieldAdapterFactoryTest.java
new file mode 100644
index 0000000..9d4b438
--- /dev/null
+++ b/gson/src/test/java/org/onap/policy/common/gson/JacksonFieldAdapterFactoryTest.java
@@ -0,0 +1,214 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2019 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.gson;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.JsonElement;
+import com.google.gson.reflect.TypeToken;
+import java.util.ArrayList;
+import java.util.List;
+import org.junit.Test;
+import org.onap.policy.common.gson.JacksonExclusionStrategy;
+import org.onap.policy.common.gson.JacksonFieldAdapterFactory;
+import org.onap.policy.common.gson.annotation.GsonJsonIgnore;
+import org.onap.policy.common.gson.annotation.GsonJsonProperty;
+
+public class JacksonFieldAdapterFactoryTest {
+
+ private static JacksonFieldAdapterFactory factory = new JacksonFieldAdapterFactory();
+
+ private static Gson gson = new GsonBuilder().setExclusionStrategies(new JacksonExclusionStrategy())
+ .registerTypeAdapterFactory(factory).create();
+
+ @Test
+ public void testCreate() {
+ // unhandled types
+ assertNull(factory.create(gson, TypeToken.get(JsonElement.class)));
+ assertNull(factory.create(gson, TypeToken.get(NothingToSerialize.class)));
+
+ assertNotNull(factory.create(gson, TypeToken.get(Data.class)));
+ assertNotNull(factory.create(gson, TypeToken.get(Derived.class)));
+
+ Data data = new Data();
+
+ // deserialize using fields that aren't in the Data object
+ Data data2 = gson.fromJson("{\"abc\":100}", Data.class);
+ assertEquals(data.toString(), data2.toString());
+
+ // now work with valid fields
+ data.id = 10;
+ data.text = "hello";
+
+ String result = gson.toJson(data);
+ data2 = gson.fromJson(result, Data.class);
+ assertEquals(data.toString(), data2.toString());
+
+ // should also work with derived types
+ Derived der = new Derived();
+ der.setId(20);
+ der.text = "world";
+ der.unserialized = "abc";
+
+ result = gson.toJson(der);
+
+ // should not contain the unserialized field
+ assertFalse(result.contains("abc"));
+
+ Derived der2 = gson.fromJson(result, Derived.class);
+ der.unserialized = null;
+ assertEquals(der.toString(), der2.toString());
+ }
+
+ @Test
+ public void testCreate_Lists() {
+ DataList lst = new DataList();
+ lst.theList = new ArrayList<>();
+ lst.theList.add(new Data(200, "text 20"));
+ lst.theList.add(new Data(210, "text 21"));
+
+ String result = gson.toJson(lst);
+ assertEquals("{'theList':[{'my-id':200,'text':'text 20'},{'my-id':210,'text':'text 21'}]}".replace('\'', '"'),
+ result);
+
+ DataList lst2 = gson.fromJson(result, DataList.class);
+ assertEquals(stripIdent(lst.toString()), stripIdent(lst2.toString()));
+ assertEquals(Data.class, lst2.theList.get(0).getClass());
+ }
+
+ @Test
+ public void testCreate_OnlyOutProps() {
+ InFieldIgnored data = new InFieldIgnored();
+ data.value = "out only";
+
+ // field should be serialized
+ String result = gson.toJson(data);
+ assertEquals("{'value':'out only'}".replace('\'', '"'), result);
+
+ // field should NOT be deserialized
+ data = gson.fromJson(result, InFieldIgnored.class);
+ assertNull(data.value);
+ }
+
+ @Test
+ public void testCreate_OnlyInProps() {
+ OutFieldIgnored data = new OutFieldIgnored();
+ data.value = "in only";
+
+ // field should NOT be serialized
+ String result = gson.toJson(data);
+ assertEquals("{}", result);
+
+ // field should NOT be deserialized
+ data = gson.fromJson("{'value':'in only'}".replace('\'', '"'), OutFieldIgnored.class);
+ assertEquals("in only", data.value);
+ }
+
+ /**
+ * Object identifiers may change with each execution, so this method is used to strip
+ * the identifier from the text string so that the strings will still match across
+ * different runs.
+ *
+ * @param text text from which to strip the identifier
+ * @return the text, without the identifier
+ */
+ private String stripIdent(String text) {
+ return text.replaceFirst("@\\w+", "@");
+ }
+
+ private static class Data {
+ @GsonJsonProperty("my-id")
+ private int id;
+
+ public String text;
+
+ public Data() {
+ super();
+ }
+
+ public Data(int id, String text) {
+ this.id = id;
+ this.text = text;
+ }
+
+ public void setId(int id) {
+ this.id = id;
+ }
+
+ @Override
+ public String toString() {
+ return "Data [id=" + id + ", text=" + text + "]";
+ }
+ }
+
+ private static class Derived extends Data {
+ // not serialized
+ private String unserialized;
+
+ @Override
+ public String toString() {
+ return "Derived [unserialized=" + unserialized + ", toString()=" + super.toString() + "]";
+ }
+ }
+
+ private static class DataList {
+ @GsonJsonProperty
+ private List<Data> theList;
+ }
+
+ protected static class NothingToSerialize {
+ // not serialized
+ protected String unserialized;
+ }
+
+ /**
+ * This has a field that should show up in the "output" list, but not in the "input"
+ * list, because the method will override it.
+ */
+ private static class InFieldIgnored {
+ @GsonJsonProperty("value")
+ private String value;
+
+ @GsonJsonIgnore
+ public void setValue(String value) {
+ this.value = value;
+ }
+ }
+
+ /**
+ * This has a field that should show up in the "input" list, but not in the "output"
+ * list, because the method will override it.
+ */
+ private static class OutFieldIgnored {
+ @GsonJsonProperty("value")
+ private String value;
+
+ @GsonJsonIgnore
+ public String getValue() {
+ return value;
+ }
+ }
+}
diff --git a/gson/src/test/java/org/onap/policy/common/gson/internal/FieldDeserializerTest.java b/gson/src/test/java/org/onap/policy/common/gson/internal/FieldDeserializerTest.java
new file mode 100644
index 0000000..62bab23
--- /dev/null
+++ b/gson/src/test/java/org/onap/policy/common/gson/internal/FieldDeserializerTest.java
@@ -0,0 +1,109 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2019 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.gson.internal;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonNull;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParseException;
+import java.util.List;
+import org.junit.Test;
+import org.onap.policy.common.gson.JacksonExclusionStrategy;
+import org.onap.policy.common.gson.internal.DataAdapterFactory.Data;
+import org.onap.policy.common.gson.internal.FieldDeserializer;
+
+public class FieldDeserializerTest {
+ private static final String TEXT_FIELD_NAME = "text";
+ private static final String LIST_FIELD_NAME = "listField";
+ private static final String INITIAL_VALUE = "initial value";
+ private static final String NEW_VALUE = "new value";
+
+ private static DataAdapterFactory dataAdapter = new DataAdapterFactory();
+
+ private static Gson gson = new GsonBuilder().registerTypeAdapterFactory(dataAdapter)
+ .setExclusionStrategies(new JacksonExclusionStrategy()).create();
+
+ private FieldDeserializer deser;
+
+ private String text;
+
+ private List<Data> listField;
+
+ @Test
+ public void testGetFromTree() throws Exception {
+ deser = new FieldDeserializer(gson, FieldDeserializerTest.class.getDeclaredField(TEXT_FIELD_NAME));
+
+ JsonObject json = new JsonObject();
+
+ // no value in tree - text remains unchanged
+ text = INITIAL_VALUE;
+ deser.getFromTree(json, this);
+ assertEquals(text, INITIAL_VALUE);
+
+ // null value in tree - text remains unchanged
+ json.add(TEXT_FIELD_NAME, JsonNull.INSTANCE);
+ deser.getFromTree(json, this);
+ assertEquals(text, INITIAL_VALUE);
+
+ // now assign a value - text should be changed now
+ json.addProperty(TEXT_FIELD_NAME, NEW_VALUE);
+
+ deser.getFromTree(json, this);
+ assertEquals(text, NEW_VALUE);
+
+ /*
+ * check list field
+ */
+ deser = new FieldDeserializer(gson, FieldDeserializerTest.class.getDeclaredField(LIST_FIELD_NAME));
+
+ json.add(LIST_FIELD_NAME, DataAdapterFactory.makeArray());
+
+ dataAdapter.reset();
+ listField = null;
+ deser.getFromTree(json, this);
+
+ assertTrue(dataAdapter.isDataRead());
+ assertEquals(DataAdapterFactory.makeList().toString(), listField.toString());
+ }
+
+ @Test
+ public void testGetFromTree_SetEx() throws Exception {
+ deser = new FieldDeserializer(gson, FieldDeserializerTest.class.getDeclaredField(TEXT_FIELD_NAME)) {
+ @Override
+ public Object fromJsonTree(JsonElement tree) {
+ // return an int, which won't fit in a String - cause an exception
+ return 10;
+ }
+ };
+
+ JsonObject json = new JsonObject();
+ json.addProperty(TEXT_FIELD_NAME, NEW_VALUE);
+
+ assertThatThrownBy(() -> deser.getFromTree(json, this)).isInstanceOf(JsonParseException.class)
+ .hasMessage(FieldDeserializer.SET_ERR + FieldDeserializerTest.class.getName() + ".text");
+ }
+}
diff --git a/gson/src/test/java/org/onap/policy/common/gson/internal/FieldSerializerTest.java b/gson/src/test/java/org/onap/policy/common/gson/internal/FieldSerializerTest.java
new file mode 100644
index 0000000..18167fc
--- /dev/null
+++ b/gson/src/test/java/org/onap/policy/common/gson/internal/FieldSerializerTest.java
@@ -0,0 +1,96 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2019 AT&T Intellectual Property. All rights reserved.
+ * ================================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.gson.internal;
+
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import com.google.gson.Gson;
+import com.google.gson.GsonBuilder;
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParseException;
+import java.util.List;
+import org.junit.Test;
+import org.onap.policy.common.gson.JacksonExclusionStrategy;
+import org.onap.policy.common.gson.internal.DataAdapterFactory.Data;
+import org.onap.policy.common.gson.internal.FieldSerializer;
+
+public class FieldSerializerTest {
+ private static final String TEXT_FIELD_NAME = "text";
+ private static final String LIST_FIELD_NAME = "listField";
+
+ private static DataAdapterFactory dataAdapter = new DataAdapterFactory();
+
+ private static Gson gson = new GsonBuilder().registerTypeAdapterFactory(dataAdapter)
+ .setExclusionStrategies(new JacksonExclusionStrategy()).create();
+
+ private FieldSerializer ser;
+
+ protected String text;
+
+ private List<Data> listField;
+
+ @Test
+ public void testAddToTree() throws Exception {
+ ser = new FieldSerializer(gson, FieldSerializerTest.class.getDeclaredField(TEXT_FIELD_NAME));
+
+ // serialize null value first
+ text = null;
+
+ JsonObject json = new JsonObject();
+ ser.addToTree(this, json);
+ assertTrue(json.get(TEXT_FIELD_NAME).isJsonNull());
+
+ // serialize an actual value
+ text = "hello";
+ ser.addToTree(this, json);
+ assertEquals("hello", json.get(TEXT_FIELD_NAME).getAsString());
+
+ /*
+ * check list field
+ */
+ listField = DataAdapterFactory.makeList();
+
+ ser = new FieldSerializer(gson, FieldSerializerTest.class.getDeclaredField(LIST_FIELD_NAME));
+
+ dataAdapter.reset();
+ JsonElement tree = ser.toJsonTree(listField);
+ assertTrue(dataAdapter.isDataWritten());
+ assertEquals(DataAdapterFactory.ENCODED_LIST, tree.toString());
+ }
+
+ @Test
+ public void testAddToTree_GetEx() throws Exception {
+ ser = new FieldSerializer(gson, FieldSerializerTest.class.getDeclaredField(TEXT_FIELD_NAME)) {
+ @Override
+ protected Object getFromObject(Object source) throws IllegalAccessException {
+ throw new IllegalAccessException("expected exception");
+ }
+ };
+
+ text = "world";
+
+ assertThatThrownBy(() -> ser.addToTree(this, new JsonObject())).isInstanceOf(JsonParseException.class)
+ .hasMessage(FieldSerializer.GET_ERR + FieldSerializerTest.class.getName() + ".text");
+ }
+}